Commit | Line | Data |
---|---|---|
e92e55da MB |
1 | package Fatal; |
2 | ||
0b09a93a | 3 | use 5.008; # 5.8.x needed for autodie |
e92e55da MB |
4 | use Carp; |
5 | use strict; | |
0b09a93a | 6 | use warnings; |
9b657a62 PF |
7 | use Tie::RefHash; # To cache subroutine refs |
8 | ||
9 | use constant PERL510 => ( $] >= 5.010 ); | |
e92e55da | 10 | |
0b09a93a PF |
11 | use constant LEXICAL_TAG => q{:lexical}; |
12 | use constant VOID_TAG => q{:void}; | |
9b657a62 | 13 | use constant INSIST_TAG => q{!}; |
e92e55da | 14 | |
0b09a93a PF |
15 | use constant ERROR_NOARGS => 'Cannot use lexical %s with no arguments'; |
16 | use constant ERROR_VOID_LEX => VOID_TAG.' cannot be used with lexical scope'; | |
17 | use constant ERROR_LEX_FIRST => LEXICAL_TAG.' must be used as first argument'; | |
18 | use constant ERROR_NO_LEX => "no %s can only start with ".LEXICAL_TAG; | |
19 | use constant ERROR_BADNAME => "Bad subroutine name for %s: %s"; | |
20 | use constant ERROR_NOTSUB => "%s is not a Perl subroutine"; | |
21 | use constant ERROR_NOT_BUILT => "%s is neither a builtin, nor a Perl subroutine"; | |
9b657a62 PF |
22 | use constant ERROR_NOHINTS => "No user hints defined for %s"; |
23 | ||
0b09a93a PF |
24 | use constant ERROR_CANT_OVERRIDE => "Cannot make the non-overridable builtin %s fatal"; |
25 | ||
26 | use constant ERROR_NO_IPC_SYS_SIMPLE => "IPC::System::Simple required for Fatalised/autodying system()"; | |
27 | ||
28 | use constant ERROR_IPC_SYS_SIMPLE_OLD => "IPC::System::Simple version %f required for Fatalised/autodying system(). We only have version %f"; | |
29 | ||
30 | use constant ERROR_AUTODIE_CONFLICT => q{"no autodie '%s'" is not allowed while "use Fatal '%s'" is in effect}; | |
31 | ||
32 | use constant ERROR_FATAL_CONFLICT => q{"use Fatal '%s'" is not allowed while "no autodie '%s'" is in effect}; | |
33 | ||
9b657a62 PF |
34 | use constant ERROR_58_HINTS => q{Non-subroutine %s hints for %s are not supported under Perl 5.8.x}; |
35 | ||
0b09a93a PF |
36 | # Older versions of IPC::System::Simple don't support all the |
37 | # features we need. | |
38 | ||
39 | use constant MIN_IPC_SYS_SIMPLE_VER => 0.12; | |
40 | ||
41 | # All the Fatal/autodie modules share the same version number. | |
b0745470 | 42 | our $VERSION = '2.06'; |
0b09a93a PF |
43 | |
44 | our $Debug ||= 0; | |
45 | ||
46 | # EWOULDBLOCK values for systems that don't supply their own. | |
47 | # Even though this is defined with our, that's to help our | |
48 | # test code. Please don't rely upon this variable existing in | |
49 | # the future. | |
50 | ||
51 | our %_EWOULDBLOCK = ( | |
52 | MSWin32 => 33, | |
53 | ); | |
54 | ||
55 | # We have some tags that can be passed in for use with import. | |
56 | # These are all assumed to be CORE:: | |
57 | ||
58 | my %TAGS = ( | |
59 | ':io' => [qw(:dbm :file :filesys :ipc :socket | |
60 | read seek sysread syswrite sysseek )], | |
61 | ':dbm' => [qw(dbmopen dbmclose)], | |
62 | ':file' => [qw(open close flock sysopen fcntl fileno binmode | |
63 | ioctl truncate)], | |
64 | ':filesys' => [qw(opendir closedir chdir link unlink rename mkdir | |
65 | symlink rmdir readlink umask)], | |
66 | ':ipc' => [qw(:msg :semaphore :shm pipe)], | |
67 | ':msg' => [qw(msgctl msgget msgrcv msgsnd)], | |
68 | ':threads' => [qw(fork)], | |
69 | ':semaphore'=>[qw(semctl semget semop)], | |
70 | ':shm' => [qw(shmctl shmget shmread)], | |
71 | ':system' => [qw(system exec)], | |
72 | ||
73 | # Can we use qw(getpeername getsockname)? What do they do on failure? | |
9b657a62 | 74 | # TODO - Can socket return false? |
0b09a93a PF |
75 | ':socket' => [qw(accept bind connect getsockopt listen recv send |
76 | setsockopt shutdown socketpair)], | |
77 | ||
78 | # Our defaults don't include system(), because it depends upon | |
79 | # an optional module, and it breaks the exotic form. | |
80 | # | |
81 | # This *may* change in the future. I'd love IPC::System::Simple | |
82 | # to be a dependency rather than a recommendation, and hence for | |
83 | # system() to be autodying by default. | |
84 | ||
85 | ':default' => [qw(:io :threads)], | |
86 | ||
87 | # Version specific tags. These allow someone to specify | |
88 | # use autodie qw(:1.994) and know exactly what they'll get. | |
89 | ||
90 | ':1.994' => [qw(:default)], | |
91 | ':1.995' => [qw(:default)], | |
92 | ':1.996' => [qw(:default)], | |
93 | ':1.997' => [qw(:default)], | |
3776a202 | 94 | ':1.998' => [qw(:default)], |
db4e6d09 | 95 | ':1.999' => [qw(:default)], |
9b657a62 PF |
96 | ':1.999_01' => [qw(:default)], |
97 | ':2.00' => [qw(:default)], | |
eb8d423f PF |
98 | ':2.01' => [qw(:default)], |
99 | ':2.02' => [qw(:default)], | |
100 | ':2.03' => [qw(:default)], | |
6c4f9c52 | 101 | ':2.04' => [qw(:default)], |
02b13d1d | 102 | ':2.05' => [qw(:default)], |
b0745470 | 103 | ':2.06' => [qw(:default)], |
0b09a93a PF |
104 | ); |
105 | ||
106 | $TAGS{':all'} = [ keys %TAGS ]; | |
107 | ||
108 | # This hash contains subroutines for which we should | |
109 | # subroutine() // die() rather than subroutine() || die() | |
110 | ||
111 | my %Use_defined_or; | |
112 | ||
113 | # CORE::open returns undef on failure. It can legitimately return | |
114 | # 0 on success, eg: open(my $fh, '-|') || exec(...); | |
115 | ||
116 | @Use_defined_or{qw( | |
117 | CORE::fork | |
118 | CORE::recv | |
119 | CORE::send | |
120 | CORE::open | |
121 | CORE::fileno | |
122 | CORE::read | |
123 | CORE::readlink | |
124 | CORE::sysread | |
125 | CORE::syswrite | |
126 | CORE::sysseek | |
127 | CORE::umask | |
128 | )} = (); | |
129 | ||
130 | # Cached_fatalised_sub caches the various versions of our | |
131 | # fatalised subs as they're produced. This means we don't | |
132 | # have to build our own replacement of CORE::open and friends | |
133 | # for every single package that wants to use them. | |
134 | ||
135 | my %Cached_fatalised_sub = (); | |
136 | ||
137 | # Every time we're called with package scope, we record the subroutine | |
138 | # (including package or CORE::) in %Package_Fatal. This allows us | |
139 | # to detect illegal combinations of autodie and Fatal, and makes sure | |
140 | # we don't accidently make a Fatal function autodying (which isn't | |
141 | # very useful). | |
142 | ||
143 | my %Package_Fatal = (); | |
144 | ||
145 | # The first time we're called with a user-sub, we cache it here. | |
146 | # In the case of a "no autodie ..." we put back the cached copy. | |
147 | ||
148 | my %Original_user_sub = (); | |
149 | ||
9b657a62 PF |
150 | # Is_fatalised_sub simply records a big map of fatalised subroutine |
151 | # refs. It means we can avoid repeating work, or fatalising something | |
152 | # we've already processed. | |
153 | ||
154 | my %Is_fatalised_sub = (); | |
155 | tie %Is_fatalised_sub, 'Tie::RefHash'; | |
156 | ||
0b09a93a PF |
157 | # We use our package in a few hash-keys. Having it in a scalar is |
158 | # convenient. The "guard $PACKAGE" string is used as a key when | |
159 | # setting up lexical guards. | |
160 | ||
161 | my $PACKAGE = __PACKAGE__; | |
162 | my $PACKAGE_GUARD = "guard $PACKAGE"; | |
163 | my $NO_PACKAGE = "no $PACKAGE"; # Used to detect 'no autodie' | |
164 | ||
165 | # Here's where all the magic happens when someone write 'use Fatal' | |
166 | # or 'use autodie'. | |
e92e55da MB |
167 | |
168 | sub import { | |
9b657a62 PF |
169 | my $class = shift(@_); |
170 | my $void = 0; | |
171 | my $lexical = 0; | |
172 | my $insist_hints = 0; | |
0b09a93a PF |
173 | |
174 | my ($pkg, $filename) = caller(); | |
175 | ||
176 | @_ or return; # 'use Fatal' is a no-op. | |
177 | ||
178 | # If we see the :lexical flag, then _all_ arguments are | |
179 | # changed lexically | |
180 | ||
181 | if ($_[0] eq LEXICAL_TAG) { | |
182 | $lexical = 1; | |
183 | shift @_; | |
184 | ||
185 | # If we see no arguments and :lexical, we assume they | |
186 | # wanted ':default'. | |
187 | ||
188 | if (@_ == 0) { | |
189 | push(@_, ':default'); | |
190 | } | |
191 | ||
192 | # Don't allow :lexical with :void, it's needlessly confusing. | |
193 | if ( grep { $_ eq VOID_TAG } @_ ) { | |
194 | croak(ERROR_VOID_LEX); | |
195 | } | |
196 | } | |
197 | ||
198 | if ( grep { $_ eq LEXICAL_TAG } @_ ) { | |
199 | # If we see the lexical tag as the non-first argument, complain. | |
200 | croak(ERROR_LEX_FIRST); | |
201 | } | |
202 | ||
203 | my @fatalise_these = @_; | |
204 | ||
205 | # Thiese subs will get unloaded at the end of lexical scope. | |
206 | my %unload_later; | |
207 | ||
208 | # This hash helps us track if we've alredy done work. | |
209 | my %done_this; | |
210 | ||
211 | # NB: we're using while/shift rather than foreach, since | |
212 | # we'll be modifying the array as we walk through it. | |
213 | ||
214 | while (my $func = shift @fatalise_these) { | |
215 | ||
216 | if ($func eq VOID_TAG) { | |
217 | ||
218 | # When we see :void, set the void flag. | |
219 | $void = 1; | |
220 | ||
9b657a62 PF |
221 | } elsif ($func eq INSIST_TAG) { |
222 | ||
223 | $insist_hints = 1; | |
224 | ||
0b09a93a PF |
225 | } elsif (exists $TAGS{$func}) { |
226 | ||
227 | # When it's a tag, expand it. | |
228 | push(@fatalise_these, @{ $TAGS{$func} }); | |
229 | ||
230 | } else { | |
231 | ||
232 | # Otherwise, fatalise it. | |
233 | ||
9b657a62 PF |
234 | # Check to see if there's an insist flag at the front. |
235 | # If so, remove it, and insist we have hints for this sub. | |
236 | my $insist_this; | |
237 | ||
238 | if ($func =~ s/^!//) { | |
239 | $insist_this = 1; | |
240 | } | |
241 | ||
242 | # TODO: Even if we've already fatalised, we should | |
243 | # check we've done it with hints (if $insist_hints). | |
244 | ||
0b09a93a PF |
245 | # If we've already made something fatal this call, |
246 | # then don't do it twice. | |
247 | ||
248 | next if $done_this{$func}; | |
249 | ||
250 | # We're going to make a subroutine fatalistic. | |
251 | # However if we're being invoked with 'use Fatal qw(x)' | |
252 | # and we've already been called with 'no autodie qw(x)' | |
253 | # in the same scope, we consider this to be an error. | |
254 | # Mixing Fatal and autodie effects was considered to be | |
255 | # needlessly confusing on p5p. | |
256 | ||
257 | my $sub = $func; | |
258 | $sub = "${pkg}::$sub" unless $sub =~ /::/; | |
259 | ||
260 | # If we're being called as Fatal, and we've previously | |
261 | # had a 'no X' in scope for the subroutine, then complain | |
262 | # bitterly. | |
263 | ||
264 | if (! $lexical and $^H{$NO_PACKAGE}{$sub}) { | |
265 | croak(sprintf(ERROR_FATAL_CONFLICT, $func, $func)); | |
266 | } | |
267 | ||
268 | # We're not being used in a confusing way, so make | |
269 | # the sub fatal. Note that _make_fatal returns the | |
270 | # old (original) version of the sub, or undef for | |
271 | # built-ins. | |
272 | ||
273 | my $sub_ref = $class->_make_fatal( | |
9b657a62 PF |
274 | $func, $pkg, $void, $lexical, $filename, |
275 | ( $insist_this || $insist_hints ) | |
0b09a93a PF |
276 | ); |
277 | ||
278 | $done_this{$func}++; | |
279 | ||
280 | $Original_user_sub{$sub} ||= $sub_ref; | |
281 | ||
282 | # If we're making lexical changes, we need to arrange | |
283 | # for them to be cleaned at the end of our scope, so | |
284 | # record them here. | |
285 | ||
286 | $unload_later{$func} = $sub_ref if $lexical; | |
287 | } | |
288 | } | |
289 | ||
290 | if ($lexical) { | |
291 | ||
292 | # Dark magic to have autodie work under 5.8 | |
293 | # Copied from namespace::clean, that copied it from | |
294 | # autobox, that found it on an ancient scroll written | |
295 | # in blood. | |
296 | ||
297 | # This magic bit causes %^H to be lexically scoped. | |
298 | ||
299 | $^H |= 0x020000; | |
300 | ||
301 | # Our package guard gets invoked when we leave our lexical | |
302 | # scope. | |
303 | ||
304 | push(@ { $^H{$PACKAGE_GUARD} }, autodie::Scope::Guard->new(sub { | |
305 | $class->_install_subs($pkg, \%unload_later); | |
306 | })); | |
307 | ||
308 | } | |
309 | ||
310 | return; | |
311 | ||
312 | } | |
313 | ||
314 | # The code here is originally lifted from namespace::clean, | |
315 | # by Robert "phaylon" Sedlacek. | |
316 | # | |
317 | # It's been redesigned after feedback from ikegami on perlmonks. | |
318 | # See http://perlmonks.org/?node_id=693338 . Ikegami rocks. | |
319 | # | |
320 | # Given a package, and hash of (subname => subref) pairs, | |
321 | # we install the given subroutines into the package. If | |
322 | # a subref is undef, the subroutine is removed. Otherwise | |
323 | # it replaces any existing subs which were already there. | |
324 | ||
325 | sub _install_subs { | |
326 | my ($class, $pkg, $subs_to_reinstate) = @_; | |
327 | ||
328 | my $pkg_sym = "${pkg}::"; | |
329 | ||
330 | while(my ($sub_name, $sub_ref) = each %$subs_to_reinstate) { | |
331 | ||
332 | my $full_path = $pkg_sym.$sub_name; | |
333 | ||
334 | # Copy symbols across to temp area. | |
335 | ||
336 | no strict 'refs'; ## no critic | |
337 | ||
338 | local *__tmp = *{ $full_path }; | |
339 | ||
340 | # Nuke the old glob. | |
341 | { no strict; delete $pkg_sym->{$sub_name}; } ## no critic | |
342 | ||
9b657a62 PF |
343 | # Copy innocent bystanders back. Note that we lose |
344 | # formats; it seems that Perl versions up to 5.10.0 | |
345 | # have a bug which causes copying formats to end up in | |
346 | # the scalar slot. Thanks to Ben Morrow for spotting this. | |
0b09a93a | 347 | |
9b657a62 | 348 | foreach my $slot (qw( SCALAR ARRAY HASH IO ) ) { |
0b09a93a PF |
349 | next unless defined *__tmp{ $slot }; |
350 | *{ $full_path } = *__tmp{ $slot }; | |
351 | } | |
352 | ||
353 | # Put back the old sub (if there was one). | |
354 | ||
355 | if ($sub_ref) { | |
356 | ||
357 | no strict; ## no critic | |
358 | *{ $pkg_sym . $sub_name } = $sub_ref; | |
359 | } | |
360 | } | |
361 | ||
362 | return; | |
363 | } | |
364 | ||
365 | sub unimport { | |
366 | my $class = shift; | |
367 | ||
368 | # Calling "no Fatal" must start with ":lexical" | |
369 | if ($_[0] ne LEXICAL_TAG) { | |
370 | croak(sprintf(ERROR_NO_LEX,$class)); | |
371 | } | |
372 | ||
373 | shift @_; # Remove :lexical | |
374 | ||
375 | my $pkg = (caller)[0]; | |
376 | ||
377 | # If we've been called with arguments, then the developer | |
378 | # has explicitly stated 'no autodie qw(blah)', | |
379 | # in which case, we disable Fatalistic behaviour for 'blah'. | |
380 | ||
381 | my @unimport_these = @_ ? @_ : ':all'; | |
382 | ||
383 | while (my $symbol = shift @unimport_these) { | |
384 | ||
385 | if ($symbol =~ /^:/) { | |
386 | ||
387 | # Looks like a tag! Expand it! | |
388 | push(@unimport_these, @{ $TAGS{$symbol} }); | |
389 | ||
390 | next; | |
391 | } | |
392 | ||
393 | my $sub = $symbol; | |
394 | $sub = "${pkg}::$sub" unless $sub =~ /::/; | |
395 | ||
396 | # If 'blah' was already enabled with Fatal (which has package | |
397 | # scope) then, this is considered an error. | |
398 | ||
399 | if (exists $Package_Fatal{$sub}) { | |
400 | croak(sprintf(ERROR_AUTODIE_CONFLICT,$symbol,$symbol)); | |
401 | } | |
402 | ||
403 | # Record 'no autodie qw($sub)' as being in effect. | |
404 | # This is to catch conflicting semantics elsewhere | |
405 | # (eg, mixing Fatal with no autodie) | |
406 | ||
407 | $^H{$NO_PACKAGE}{$sub} = 1; | |
408 | ||
409 | if (my $original_sub = $Original_user_sub{$sub}) { | |
410 | # Hey, we've got an original one of these, put it back. | |
411 | $class->_install_subs($pkg, { $symbol => $original_sub }); | |
412 | next; | |
413 | } | |
414 | ||
415 | # We don't have an original copy of the sub, on the assumption | |
416 | # it's core (or doesn't exist), we'll just nuke it. | |
417 | ||
418 | $class->_install_subs($pkg,{ $symbol => undef }); | |
419 | ||
420 | } | |
421 | ||
422 | return; | |
423 | ||
424 | } | |
425 | ||
426 | # TODO - This is rather terribly inefficient right now. | |
427 | ||
428 | # NB: Perl::Critic's dump-autodie-tag-contents depends upon this | |
429 | # continuing to work. | |
430 | ||
431 | { | |
432 | my %tag_cache; | |
433 | ||
434 | sub _expand_tag { | |
435 | my ($class, $tag) = @_; | |
436 | ||
437 | if (my $cached = $tag_cache{$tag}) { | |
438 | return $cached; | |
439 | } | |
440 | ||
441 | if (not exists $TAGS{$tag}) { | |
442 | croak "Invalid exception class $tag"; | |
443 | } | |
444 | ||
445 | my @to_process = @{$TAGS{$tag}}; | |
446 | ||
447 | my @taglist = (); | |
448 | ||
449 | while (my $item = shift @to_process) { | |
450 | if ($item =~ /^:/) { | |
451 | push(@to_process, @{$TAGS{$item}} ); | |
452 | } else { | |
453 | push(@taglist, "CORE::$item"); | |
454 | } | |
455 | } | |
456 | ||
457 | $tag_cache{$tag} = \@taglist; | |
458 | ||
459 | return \@taglist; | |
460 | ||
461 | } | |
462 | ||
e92e55da MB |
463 | } |
464 | ||
0b09a93a | 465 | # This code is from the original Fatal. It scares me. |
9b657a62 PF |
466 | # It is 100% compatible with the 5.10.0 Fatal module, right down |
467 | # to the scary 'XXXX' comment. ;) | |
0b09a93a | 468 | |
e92e55da | 469 | sub fill_protos { |
0b09a93a PF |
470 | my $proto = shift; |
471 | my ($n, $isref, @out, @out1, $seen_semi) = -1; | |
472 | while ($proto =~ /\S/) { | |
473 | $n++; | |
474 | push(@out1,[$n,@out]) if $seen_semi; | |
475 | push(@out, $1 . "{\$_[$n]}"), next if $proto =~ s/^\s*\\([\@%\$\&])//; | |
476 | push(@out, "\$_[$n]"), next if $proto =~ s/^\s*([_*\$&])//; | |
477 | push(@out, "\@_[$n..\$#_]"), last if $proto =~ s/^\s*(;\s*)?\@//; | |
478 | $seen_semi = 1, $n--, next if $proto =~ s/^\s*;//; # XXXX ???? | |
479 | die "Internal error: Unknown prototype letters: \"$proto\""; | |
480 | } | |
481 | push(@out1,[$n+1,@out]); | |
482 | return @out1; | |
e92e55da MB |
483 | } |
484 | ||
9b657a62 PF |
485 | # This is a backwards compatible version of _write_invocation. It's |
486 | # recommended you don't use it. | |
0b09a93a | 487 | |
e92e55da | 488 | sub write_invocation { |
9b657a62 PF |
489 | my ($core, $call, $name, $void, @args) = @_; |
490 | ||
491 | return Fatal->_write_invocation( | |
492 | $core, $call, $name, $void, | |
493 | 0, # Lexical flag | |
494 | undef, # Sub, unused in legacy mode | |
495 | undef, # Subref, unused in legacy mode. | |
496 | @args | |
497 | ); | |
498 | } | |
499 | ||
500 | # This version of _write_invocation is used internally. It's not | |
501 | # recommended you call it from external code, as the interface WILL | |
502 | # change in the future. | |
503 | ||
504 | sub _write_invocation { | |
505 | ||
506 | my ($class, $core, $call, $name, $void, $lexical, $sub, $sref, @argvs) = @_; | |
0b09a93a PF |
507 | |
508 | if (@argvs == 1) { # No optional arguments | |
509 | ||
510 | my @argv = @{$argvs[0]}; | |
511 | shift @argv; | |
512 | ||
9b657a62 | 513 | return $class->_one_invocation($core,$call,$name,$void,$sub,! $lexical, $sref, @argv); |
0b09a93a PF |
514 | |
515 | } else { | |
516 | my $else = "\t"; | |
517 | my (@out, @argv, $n); | |
518 | while (@argvs) { | |
519 | @argv = @{shift @argvs}; | |
520 | $n = shift @argv; | |
521 | ||
522 | push @out, "${else}if (\@_ == $n) {\n"; | |
523 | $else = "\t} els"; | |
524 | ||
9b657a62 | 525 | push @out, $class->_one_invocation($core,$call,$name,$void,$sub,! $lexical, $sref, @argv); |
0b09a93a | 526 | } |
9b657a62 | 527 | push @out, qq[ |
0b09a93a | 528 | } |
9b657a62 | 529 | die "Internal error: $name(\@_): Do not expect to get ", scalar(\@_), " arguments"; |
0b09a93a PF |
530 | ]; |
531 | ||
532 | return join '', @out; | |
533 | } | |
e92e55da MB |
534 | } |
535 | ||
9b657a62 PF |
536 | |
537 | # This is a slim interface to ensure backward compatibility with | |
538 | # anyone doing very foolish things with old versions of Fatal. | |
539 | ||
e92e55da | 540 | sub one_invocation { |
9b657a62 PF |
541 | my ($core, $call, $name, $void, @argv) = @_; |
542 | ||
543 | return Fatal->_one_invocation( | |
544 | $core, $call, $name, $void, | |
545 | undef, # Sub. Unused in back-compat mode. | |
546 | 1, # Back-compat flag | |
547 | undef, # Subref, unused in back-compat mode. | |
548 | @argv | |
549 | ); | |
550 | ||
551 | } | |
552 | ||
553 | # This is the internal interface that generates code. | |
554 | # NOTE: This interface WILL change in the future. Please do not | |
555 | # call this subroutine directly. | |
556 | ||
557 | # TODO: Whatever's calling this code has already looked up hints. Pass | |
558 | # them in, rather than look them up a second time. | |
559 | ||
560 | sub _one_invocation { | |
561 | my ($class, $core, $call, $name, $void, $sub, $back_compat, $sref, @argv) = @_; | |
562 | ||
0b09a93a PF |
563 | |
564 | # If someone is calling us directly (a child class perhaps?) then | |
565 | # they could try to mix void without enabling backwards | |
566 | # compatibility. We just don't support this at all, so we gripe | |
567 | # about it rather than doing something unwise. | |
568 | ||
569 | if ($void and not $back_compat) { | |
570 | Carp::confess("Internal error: :void mode not supported with $class"); | |
571 | } | |
572 | ||
573 | # @argv only contains the results of the in-built prototype | |
574 | # function, and is therefore safe to interpolate in the | |
575 | # code generators below. | |
576 | ||
577 | # TODO - The following clobbers context, but that's what the | |
578 | # old Fatal did. Do we care? | |
579 | ||
580 | if ($back_compat) { | |
581 | ||
9b657a62 PF |
582 | # Use Fatal qw(system) will never be supported. It generated |
583 | # a compile-time error with legacy Fatal, and there's no reason | |
584 | # to support it when autodie does a better job. | |
0b09a93a PF |
585 | |
586 | if ($call eq 'CORE::system') { | |
587 | return q{ | |
9b657a62 | 588 | croak("UNIMPLEMENTED: use Fatal qw(system) not supported."); |
0b09a93a PF |
589 | }; |
590 | } | |
591 | ||
592 | local $" = ', '; | |
593 | ||
594 | if ($void) { | |
595 | return qq/return (defined wantarray)?$call(@argv): | |
596 | $call(@argv) || croak "Can't $name(\@_)/ . | |
597 | ($core ? ': $!' : ', \$! is \"$!\"') . '"' | |
598 | } else { | |
599 | return qq{return $call(@argv) || croak "Can't $name(\@_)} . | |
600 | ($core ? ': $!' : ', \$! is \"$!\"') . '"'; | |
601 | } | |
602 | } | |
603 | ||
604 | # The name of our original function is: | |
605 | # $call if the function is CORE | |
606 | # $sub if our function is non-CORE | |
607 | ||
608 | # The reason for this is that $call is what we're actualling | |
609 | # calling. For our core functions, this is always | |
610 | # CORE::something. However for user-defined subs, we're about to | |
611 | # replace whatever it is that we're calling; as such, we actually | |
612 | # calling a subroutine ref. | |
613 | ||
9b657a62 PF |
614 | my $human_sub_name = $core ? $call : $sub; |
615 | ||
616 | # Should we be testing to see if our result is defined, or | |
617 | # just true? | |
618 | ||
619 | my $use_defined_or; | |
620 | ||
621 | my $hints; # All user-sub hints, including list hints. | |
622 | ||
623 | if ( $core ) { | |
624 | ||
625 | # Core hints are built into autodie. | |
626 | ||
627 | $use_defined_or = exists ( $Use_defined_or{$call} ); | |
628 | ||
629 | } | |
630 | else { | |
631 | ||
632 | # User sub hints are looked up using autodie::hints, | |
633 | # since users may wish to add their own hints. | |
634 | ||
635 | require autodie::hints; | |
636 | ||
637 | $hints = autodie::hints->get_hints_for( $sref ); | |
eb8d423f PF |
638 | |
639 | # We'll look up the sub's fullname. This means we | |
640 | # get better reports of where it came from in our | |
641 | # error messages, rather than what imported it. | |
642 | ||
643 | $human_sub_name = autodie::hints->sub_fullname( $sref ); | |
644 | ||
9b657a62 | 645 | } |
0b09a93a | 646 | |
9b657a62 | 647 | # Checks for special core subs. |
0b09a93a PF |
648 | |
649 | if ($call eq 'CORE::system') { | |
650 | ||
651 | # Leverage IPC::System::Simple if we're making an autodying | |
652 | # system. | |
653 | ||
654 | local $" = ", "; | |
655 | ||
656 | # We need to stash $@ into $E, rather than using | |
657 | # local $@ for the whole sub. If we don't then | |
658 | # any exceptions from internal errors in autodie/Fatal | |
659 | # will mysteriously disappear before propogating | |
660 | # upwards. | |
661 | ||
662 | return qq{ | |
663 | my \$retval; | |
664 | my \$E; | |
665 | ||
666 | ||
667 | { | |
668 | local \$@; | |
669 | ||
670 | eval { | |
671 | \$retval = IPC::System::Simple::system(@argv); | |
672 | }; | |
673 | ||
674 | \$E = \$@; | |
675 | } | |
676 | ||
677 | if (\$E) { | |
678 | ||
9b657a62 | 679 | # TODO - This can't be overridden in child |
0b09a93a PF |
680 | # classes! |
681 | ||
682 | die autodie::exception::system->new( | |
683 | function => q{CORE::system}, args => [ @argv ], | |
684 | message => "\$E", errno => \$!, | |
685 | ); | |
686 | } | |
687 | ||
688 | return \$retval; | |
689 | }; | |
690 | ||
691 | } | |
692 | ||
0b09a93a PF |
693 | local $" = ', '; |
694 | ||
695 | # If we're going to throw an exception, here's the code to use. | |
696 | my $die = qq{ | |
697 | die $class->throw( | |
9b657a62 | 698 | function => q{$human_sub_name}, args => [ @argv ], |
0b09a93a | 699 | pragma => q{$class}, errno => \$!, |
eb8d423f | 700 | context => \$context, return => \$retval, |
0b09a93a PF |
701 | ) |
702 | }; | |
703 | ||
704 | if ($call eq 'CORE::flock') { | |
705 | ||
706 | # flock needs special treatment. When it fails with | |
707 | # LOCK_UN and EWOULDBLOCK, then it's not really fatal, it just | |
708 | # means we couldn't get the lock right now. | |
709 | ||
710 | require POSIX; # For POSIX::EWOULDBLOCK | |
711 | ||
712 | local $@; # Don't blat anyone else's $@. | |
713 | ||
714 | # Ensure that our vendor supports EWOULDBLOCK. If they | |
715 | # don't (eg, Windows), then we use known values for its | |
716 | # equivalent on other systems. | |
717 | ||
718 | my $EWOULDBLOCK = eval { POSIX::EWOULDBLOCK(); } | |
719 | || $_EWOULDBLOCK{$^O} | |
720 | || _autocroak("Internal error - can't overload flock - EWOULDBLOCK not defined on this system."); | |
721 | ||
722 | require Fcntl; # For Fcntl::LOCK_NB | |
723 | ||
724 | return qq{ | |
725 | ||
eb8d423f PF |
726 | my \$context = wantarray() ? "list" : "scalar"; |
727 | ||
0b09a93a PF |
728 | # Try to flock. If successful, return it immediately. |
729 | ||
730 | my \$retval = $call(@argv); | |
731 | return \$retval if \$retval; | |
732 | ||
733 | # If we failed, but we're using LOCK_NB and | |
734 | # returned EWOULDBLOCK, it's not a real error. | |
735 | ||
736 | if (\$_[1] & Fcntl::LOCK_NB() and \$! == $EWOULDBLOCK ) { | |
737 | return \$retval; | |
738 | } | |
739 | ||
740 | # Otherwise, we failed. Die noisily. | |
741 | ||
742 | $die; | |
743 | ||
744 | }; | |
745 | } | |
746 | ||
747 | # AFAIK everything that can be given an unopned filehandle | |
748 | # will fail if it tries to use it, so we don't really need | |
749 | # the 'unopened' warning class here. Especially since they | |
750 | # then report the wrong line number. | |
751 | ||
eb8d423f PF |
752 | # Other warnings are disabled because they produce excessive |
753 | # complaints from smart-match hints under 5.10.1. | |
754 | ||
9b657a62 | 755 | my $code = qq[ |
eb8d423f | 756 | no warnings qw(unopened uninitialized numeric); |
0b09a93a PF |
757 | |
758 | if (wantarray) { | |
759 | my \@results = $call(@argv); | |
eb8d423f PF |
760 | my \$retval = \\\@results; |
761 | my \$context = "list"; | |
9b657a62 PF |
762 | |
763 | ]; | |
764 | ||
765 | if ( $hints and ( ref($hints->{list} ) || "" ) eq 'CODE' ) { | |
766 | ||
767 | # NB: Subroutine hints are passed as a full list. | |
768 | # This differs from the 5.10.0 smart-match behaviour, | |
769 | # but means that context unaware subroutines can use | |
770 | # the same hints in both list and scalar context. | |
771 | ||
772 | $code .= qq{ | |
773 | if ( \$hints->{list}->(\@results) ) { $die }; | |
774 | }; | |
775 | } | |
776 | elsif ( PERL510 and $hints ) { | |
777 | $code .= qq{ | |
778 | if ( \@results ~~ \$hints->{list} ) { $die }; | |
779 | }; | |
780 | } | |
781 | elsif ( $hints ) { | |
782 | croak sprintf(ERROR_58_HINTS, 'list', $sub); | |
783 | } | |
784 | else { | |
785 | $code .= qq{ | |
786 | # An empty list, or a single undef is failure | |
0b09a93a PF |
787 | if (! \@results or (\@results == 1 and ! defined \$results[0])) { |
788 | $die; | |
9b657a62 PF |
789 | } |
790 | } | |
791 | } | |
792 | ||
793 | # Tidy up the end of our wantarray call. | |
794 | ||
795 | $code .= qq[ | |
0b09a93a PF |
796 | return \@results; |
797 | } | |
9b657a62 | 798 | ]; |
0b09a93a | 799 | |
0b09a93a | 800 | |
9b657a62 PF |
801 | # Otherwise, we're in scalar context. |
802 | # We're never in a void context, since we have to look | |
803 | # at the result. | |
804 | ||
805 | $code .= qq{ | |
eb8d423f PF |
806 | my \$retval = $call(@argv); |
807 | my \$context = "scalar"; | |
9b657a62 PF |
808 | }; |
809 | ||
810 | if ( $hints and ( ref($hints->{scalar} ) || "" ) eq 'CODE' ) { | |
811 | ||
812 | # We always call code refs directly, since that always | |
813 | # works in 5.8.x, and always works in 5.10.1 | |
814 | ||
815 | return $code .= qq{ | |
eb8d423f PF |
816 | if ( \$hints->{scalar}->(\$retval) ) { $die }; |
817 | return \$retval; | |
9b657a62 | 818 | }; |
0b09a93a | 819 | |
9b657a62 PF |
820 | } |
821 | elsif (PERL510 and $hints) { | |
822 | return $code . qq{ | |
823 | ||
eb8d423f | 824 | if ( \$retval ~~ \$hints->{scalar} ) { $die }; |
9b657a62 | 825 | |
eb8d423f | 826 | return \$retval; |
9b657a62 PF |
827 | }; |
828 | } | |
829 | elsif ( $hints ) { | |
830 | croak sprintf(ERROR_58_HINTS, 'scalar', $sub); | |
831 | } | |
832 | ||
833 | return $code . | |
834 | ( $use_defined_or ? qq{ | |
0b09a93a | 835 | |
eb8d423f | 836 | $die if not defined \$retval; |
0b09a93a | 837 | |
eb8d423f | 838 | return \$retval; |
0b09a93a PF |
839 | |
840 | } : qq{ | |
841 | ||
eb8d423f | 842 | return \$retval || $die; |
0b09a93a PF |
843 | |
844 | } ) ; | |
845 | ||
e92e55da MB |
846 | } |
847 | ||
0b09a93a PF |
848 | # This returns the old copy of the sub, so we can |
849 | # put it back at end of scope. | |
850 | ||
851 | # TODO : Check to make sure prototypes are restored correctly. | |
852 | ||
853 | # TODO: Taking a huge list of arguments is awful. Rewriting to | |
854 | # take a hash would be lovely. | |
855 | ||
9b657a62 PF |
856 | # TODO - BACKCOMPAT - This is not yet compatible with 5.10.0 |
857 | ||
e92e55da | 858 | sub _make_fatal { |
9b657a62 PF |
859 | my($class, $sub, $pkg, $void, $lexical, $filename, $insist) = @_; |
860 | my($name, $code, $sref, $real_proto, $proto, $core, $call, $hints); | |
e92e55da MB |
861 | my $ini = $sub; |
862 | ||
863 | $sub = "${pkg}::$sub" unless $sub =~ /::/; | |
0b09a93a PF |
864 | |
865 | # Figure if we're using lexical or package semantics and | |
866 | # twiddle the appropriate bits. | |
867 | ||
868 | if (not $lexical) { | |
869 | $Package_Fatal{$sub} = 1; | |
870 | } | |
871 | ||
872 | # TODO - We *should* be able to do skipping, since we know when | |
873 | # we've lexicalised / unlexicalised a subroutine. | |
874 | ||
e92e55da MB |
875 | $name = $sub; |
876 | $name =~ s/.*::// or $name =~ s/^&//; | |
0b09a93a PF |
877 | |
878 | warn "# _make_fatal: sub=$sub pkg=$pkg name=$name void=$void\n" if $Debug; | |
879 | croak(sprintf(ERROR_BADNAME, $class, $name)) unless $name =~ /^\w+$/; | |
880 | ||
881 | if (defined(&$sub)) { # user subroutine | |
882 | ||
9b657a62 PF |
883 | # NOTE: Previously we would localise $@ at this point, so |
884 | # the following calls to eval {} wouldn't interfere with anything | |
885 | # that's already in $@. Unfortunately, it would also stop | |
886 | # any of our croaks from triggering(!), which is even worse. | |
887 | ||
0b09a93a PF |
888 | # This could be something that we've fatalised that |
889 | # was in core. | |
890 | ||
9b657a62 | 891 | if ( $Package_Fatal{$sub} and do { local $@; eval { prototype "CORE::$name" } } ) { |
0b09a93a PF |
892 | |
893 | # Something we previously made Fatal that was core. | |
894 | # This is safe to replace with an autodying to core | |
895 | # version. | |
896 | ||
897 | $core = 1; | |
898 | $call = "CORE::$name"; | |
899 | $proto = prototype $call; | |
900 | ||
901 | # We return our $sref from this subroutine later | |
902 | # on, indicating this subroutine should be placed | |
903 | # back when we're finished. | |
904 | ||
905 | $sref = \&$sub; | |
906 | ||
907 | } else { | |
908 | ||
9b657a62 PF |
909 | # If this is something we've already fatalised or played with, |
910 | # then look-up the name of the original sub for the rest of | |
911 | # our processing. | |
912 | ||
913 | $sub = $Is_fatalised_sub{\&$sub} || $sub; | |
914 | ||
0b09a93a PF |
915 | # A regular user sub, or a user sub wrapping a |
916 | # core sub. | |
917 | ||
918 | $sref = \&$sub; | |
919 | $proto = prototype $sref; | |
920 | $call = '&$sref'; | |
9b657a62 PF |
921 | require autodie::hints; |
922 | ||
923 | $hints = autodie::hints->get_hints_for( $sref ); | |
924 | ||
925 | # If we've insisted on hints, but don't have them, then | |
926 | # bail out! | |
927 | ||
928 | if ($insist and not $hints) { | |
929 | croak(sprintf(ERROR_NOHINTS, $name)); | |
930 | } | |
931 | ||
932 | # Otherwise, use the default hints if we don't have | |
933 | # any. | |
934 | ||
935 | $hints ||= autodie::hints::DEFAULT_HINTS(); | |
0b09a93a PF |
936 | |
937 | } | |
938 | ||
910ad8dd | 939 | } elsif ($sub eq $ini && $sub !~ /^CORE::GLOBAL::/) { |
0b09a93a PF |
940 | # Stray user subroutine |
941 | croak(sprintf(ERROR_NOTSUB,$sub)); | |
942 | ||
943 | } elsif ($name eq 'system') { | |
944 | ||
945 | # If we're fatalising system, then we need to load | |
946 | # helper code. | |
947 | ||
9b657a62 PF |
948 | # The business with $E is to avoid clobbering our caller's |
949 | # $@, and to avoid $@ being localised when we croak. | |
0b09a93a | 950 | |
9b657a62 | 951 | my $E; |
0b09a93a | 952 | |
9b657a62 PF |
953 | { |
954 | local $@; | |
955 | ||
956 | eval { | |
957 | require IPC::System::Simple; # Only load it if we need it. | |
958 | require autodie::exception::system; | |
959 | }; | |
960 | $E = $@; | |
961 | } | |
962 | ||
963 | if ($E) { croak ERROR_NO_IPC_SYS_SIMPLE; } | |
964 | ||
965 | # Make sure we're using a recent version of ISS that actually | |
966 | # support fatalised system. | |
967 | if ($IPC::System::Simple::VERSION < MIN_IPC_SYS_SIMPLE_VER) { | |
968 | croak sprintf( | |
969 | ERROR_IPC_SYS_SIMPLE_OLD, MIN_IPC_SYS_SIMPLE_VER, | |
970 | $IPC::System::Simple::VERSION | |
971 | ); | |
972 | } | |
0b09a93a PF |
973 | |
974 | $call = 'CORE::system'; | |
975 | $name = 'system'; | |
db4e6d09 | 976 | $core = 1; |
0b09a93a PF |
977 | |
978 | } elsif ($name eq 'exec') { | |
979 | # Exec doesn't have a prototype. We don't care. This | |
980 | # breaks the exotic form with lexical scope, and gives | |
981 | # the regular form a "do or die" beaviour as expected. | |
982 | ||
983 | $call = 'CORE::exec'; | |
984 | $name = 'exec'; | |
985 | $core = 1; | |
986 | ||
987 | } else { # CORE subroutine | |
9b657a62 PF |
988 | my $E; |
989 | { | |
990 | local $@; | |
991 | $proto = eval { prototype "CORE::$name" }; | |
992 | $E = $@; | |
993 | } | |
994 | croak(sprintf(ERROR_NOT_BUILT,$name)) if $E; | |
0b09a93a PF |
995 | croak(sprintf(ERROR_CANT_OVERRIDE,$name)) if not defined $proto; |
996 | $core = 1; | |
997 | $call = "CORE::$name"; | |
e92e55da | 998 | } |
0b09a93a | 999 | |
e92e55da | 1000 | if (defined $proto) { |
0b09a93a | 1001 | $real_proto = " ($proto)"; |
e92e55da | 1002 | } else { |
0b09a93a PF |
1003 | $real_proto = ''; |
1004 | $proto = '@'; | |
1005 | } | |
1006 | ||
1007 | my $true_name = $core ? $call : $sub; | |
1008 | ||
1009 | # TODO: This caching works, but I don't like using $void and | |
1010 | # $lexical as keys. In particular, I suspect our code may end up | |
1011 | # wrapping already wrapped code when autodie and Fatal are used | |
1012 | # together. | |
1013 | ||
1014 | # NB: We must use '$sub' (the name plus package) and not | |
1015 | # just '$name' (the short name) here. Failing to do so | |
1016 | # results code that's in the wrong package, and hence has | |
1017 | # access to the wrong package filehandles. | |
1018 | ||
1019 | if (my $subref = $Cached_fatalised_sub{$class}{$sub}{$void}{$lexical}) { | |
1020 | $class->_install_subs($pkg, { $name => $subref }); | |
1021 | return $sref; | |
e92e55da | 1022 | } |
0b09a93a PF |
1023 | |
1024 | $code = qq[ | |
1025 | sub$real_proto { | |
1026 | local(\$", \$!) = (', ', 0); # TODO - Why do we do this? | |
1027 | ]; | |
1028 | ||
1029 | # Don't have perl whine if exec fails, since we'll be handling | |
1030 | # the exception now. | |
1031 | $code .= "no warnings qw(exec);\n" if $call eq "CORE::exec"; | |
1032 | ||
e92e55da | 1033 | my @protos = fill_protos($proto); |
9b657a62 | 1034 | $code .= $class->_write_invocation($core, $call, $name, $void, $lexical, $sub, $sref, @protos); |
e92e55da | 1035 | $code .= "}\n"; |
0b09a93a PF |
1036 | warn $code if $Debug; |
1037 | ||
1038 | # I thought that changing package was a monumental waste of | |
1039 | # time for CORE subs, since they'll always be the same. However | |
1040 | # that's not the case, since they may refer to package-based | |
1041 | # filehandles (eg, with open). | |
1042 | # | |
1043 | # There is potential to more aggressively cache core subs | |
1044 | # that we know will never want to interact with package variables | |
1045 | # and filehandles. | |
1046 | ||
2ba6ecf4 | 1047 | { |
0b09a93a | 1048 | no strict 'refs'; ## no critic # to avoid: Can't use string (...) as a symbol ref ... |
0b09a93a | 1049 | |
9b657a62 PF |
1050 | my $E; |
1051 | ||
1052 | { | |
1053 | local $@; | |
1054 | $code = eval("package $pkg; use Carp; $code"); ## no critic | |
1055 | $E = $@; | |
1056 | } | |
0b09a93a | 1057 | |
9b657a62 PF |
1058 | if (not $code) { |
1059 | croak("Internal error in autodie/Fatal processing $true_name: $E"); | |
0b09a93a PF |
1060 | |
1061 | } | |
1062 | } | |
1063 | ||
1064 | # Now we need to wrap our fatalised sub inside an itty bitty | |
1065 | # closure, which can detect if we've leaked into another file. | |
1066 | # Luckily, we only need to do this for lexical (autodie) | |
1067 | # subs. Fatal subs can leak all they want, it's considered | |
1068 | # a "feature" (or at least backwards compatible). | |
1069 | ||
1070 | # TODO: Cache our leak guards! | |
1071 | ||
1072 | # TODO: This is pretty hairy code. A lot more tests would | |
1073 | # be really nice for this. | |
1074 | ||
1075 | my $leak_guard; | |
1076 | ||
1077 | if ($lexical) { | |
1078 | ||
1079 | $leak_guard = qq< | |
1080 | package $pkg; | |
1081 | ||
1082 | sub$real_proto { | |
1083 | ||
db4e6d09 PF |
1084 | # If we're inside a string eval, we can end up with a |
1085 | # whacky filename. The following code allows autodie | |
1086 | # to propagate correctly into string evals. | |
1087 | ||
1088 | my \$caller_level = 0; | |
1089 | ||
b0745470 PF |
1090 | my \$caller; |
1091 | ||
1092 | while ( (\$caller = (caller \$caller_level)[1]) =~ m{^\\(eval \\d+\\)\$} ) { | |
1093 | ||
1094 | # If our filename is actually an eval, and we | |
1095 | # reach it, then go to our autodying code immediatately. | |
1096 | ||
1097 | goto &\$code if (\$caller eq \$filename); | |
db4e6d09 PF |
1098 | \$caller_level++; |
1099 | } | |
1100 | ||
b0745470 PF |
1101 | # We're now out of the eval stack. |
1102 | ||
0b09a93a PF |
1103 | # If we're called from the correct file, then use the |
1104 | # autodying code. | |
db4e6d09 | 1105 | goto &\$code if ((caller \$caller_level)[1] eq \$filename); |
0b09a93a PF |
1106 | |
1107 | # Oh bother, we've leaked into another file. Call the | |
1108 | # original code. Note that \$sref may actually be a | |
1109 | # reference to a Fatalised version of a core built-in. | |
1110 | # That's okay, because Fatal *always* leaks between files. | |
1111 | ||
1112 | goto &\$sref if \$sref; | |
1113 | >; | |
1114 | ||
1115 | ||
1116 | # If we're here, it must have been a core subroutine called. | |
1117 | # Warning: The following code may disturb some viewers. | |
1118 | ||
1119 | # TODO: It should be possible to combine this with | |
1120 | # write_invocation(). | |
1121 | ||
1122 | foreach my $proto (@protos) { | |
1123 | local $" = ", "; # So @args is formatted correctly. | |
1124 | my ($count, @args) = @$proto; | |
1125 | $leak_guard .= qq< | |
1126 | if (\@_ == $count) { | |
1127 | return $call(@args); | |
1128 | } | |
1129 | >; | |
1130 | } | |
1131 | ||
1132 | $leak_guard .= qq< croak "Internal error in Fatal/autodie. Leak-guard failure"; } >; | |
1133 | ||
1134 | # warn "$leak_guard\n"; | |
1135 | ||
9b657a62 PF |
1136 | my $E; |
1137 | { | |
1138 | local $@; | |
1139 | ||
1140 | $leak_guard = eval $leak_guard; ## no critic | |
0b09a93a | 1141 | |
9b657a62 PF |
1142 | $E = $@; |
1143 | } | |
0b09a93a | 1144 | |
9b657a62 | 1145 | die "Internal error in $class: Leak-guard installation failure: $E" if $E; |
0b09a93a PF |
1146 | } |
1147 | ||
9b657a62 PF |
1148 | my $installed_sub = $leak_guard || $code; |
1149 | ||
1150 | $class->_install_subs($pkg, { $name => $installed_sub }); | |
1151 | ||
1152 | $Cached_fatalised_sub{$class}{$sub}{$void}{$lexical} = $installed_sub; | |
1153 | ||
1154 | # Cache that we've now overriddent this sub. If we get called | |
1155 | # again, we may need to find that find subroutine again (eg, for hints). | |
0b09a93a | 1156 | |
9b657a62 | 1157 | $Is_fatalised_sub{$installed_sub} = $sref; |
0b09a93a PF |
1158 | |
1159 | return $sref; | |
1160 | ||
1161 | } | |
1162 | ||
1163 | # This subroutine exists primarily so that child classes can override | |
1164 | # it to point to their own exception class. Doing this is significantly | |
1165 | # less complex than overriding throw() | |
1166 | ||
1167 | sub exception_class { return "autodie::exception" }; | |
1168 | ||
1169 | { | |
1170 | my %exception_class_for; | |
1171 | my %class_loaded; | |
1172 | ||
1173 | sub throw { | |
1174 | my ($class, @args) = @_; | |
1175 | ||
1176 | # Find our exception class if we need it. | |
1177 | my $exception_class = | |
1178 | $exception_class_for{$class} ||= $class->exception_class; | |
1179 | ||
1180 | if (not $class_loaded{$exception_class}) { | |
1181 | if ($exception_class =~ /[^\w:']/) { | |
1182 | confess "Bad exception class '$exception_class'.\nThe '$class->exception_class' method wants to use $exception_class\nfor exceptions, but it contains characters which are not word-characters or colons."; | |
1183 | } | |
1184 | ||
1185 | # Alas, Perl does turn barewords into modules unless they're | |
1186 | # actually barewords. As such, we're left doing a string eval | |
1187 | # to make sure we load our file correctly. | |
1188 | ||
1189 | my $E; | |
1190 | ||
1191 | { | |
1192 | local $@; # We can't clobber $@, it's wrong! | |
1193 | eval "require $exception_class"; ## no critic | |
1194 | $E = $@; # Save $E despite ending our local. | |
1195 | } | |
1196 | ||
1197 | # We need quotes around $@ to make sure it's stringified | |
1198 | # while still in scope. Without them, we run the risk of | |
1199 | # $@ having been cleared by us exiting the local() block. | |
1200 | ||
1201 | confess "Failed to load '$exception_class'.\nThis may be a typo in the '$class->exception_class' method,\nor the '$exception_class' module may not exist.\n\n $E" if $E; | |
1202 | ||
1203 | $class_loaded{$exception_class}++; | |
1204 | ||
1205 | } | |
1206 | ||
1207 | return $exception_class->new(@args); | |
2ba6ecf4 | 1208 | } |
e92e55da MB |
1209 | } |
1210 | ||
0b09a93a PF |
1211 | # For some reason, dying while replacing our subs doesn't |
1212 | # kill our calling program. It simply stops the loading of | |
1213 | # autodie and keeps going with everything else. The _autocroak | |
1214 | # sub allows us to die with a vegence. It should *only* ever be | |
1215 | # used for serious internal errors, since the results of it can't | |
1216 | # be captured. | |
1217 | ||
1218 | sub _autocroak { | |
1219 | warn Carp::longmess(@_); | |
1220 | exit(255); # Ugh! | |
1221 | } | |
1222 | ||
1223 | package autodie::Scope::Guard; | |
1224 | ||
1225 | # This code schedules the cleanup of subroutines at the end of | |
1226 | # scope. It's directly inspired by chocolateboy's excellent | |
1227 | # Scope::Guard module. | |
1228 | ||
1229 | sub new { | |
1230 | my ($class, $handler) = @_; | |
1231 | ||
1232 | return bless $handler, $class; | |
1233 | } | |
1234 | ||
1235 | sub DESTROY { | |
1236 | my ($self) = @_; | |
1237 | ||
1238 | $self->(); | |
1239 | } | |
1240 | ||
e92e55da MB |
1241 | 1; |
1242 | ||
1243 | __END__ | |
1244 | ||
1245 | =head1 NAME | |
1246 | ||
0b09a93a | 1247 | Fatal - Replace functions with equivalents which succeed or die |
e92e55da MB |
1248 | |
1249 | =head1 SYNOPSIS | |
1250 | ||
1251 | use Fatal qw(open close); | |
1252 | ||
0b09a93a PF |
1253 | open(my $fh, "<", $filename); # No need to check errors! |
1254 | ||
1255 | use File::Copy qw(move); | |
1256 | use Fatal qw(move); | |
1257 | ||
1258 | move($file1, $file2); # No need to check errors! | |
1259 | ||
e92e55da | 1260 | sub juggle { . . . } |
0b09a93a PF |
1261 | Fatal->import('juggle'); |
1262 | ||
1263 | =head1 BEST PRACTICE | |
1264 | ||
1265 | B<Fatal has been obsoleted by the new L<autodie> pragma.> Please use | |
1266 | L<autodie> in preference to C<Fatal>. L<autodie> supports lexical scoping, | |
1267 | throws real exception objects, and provides much nicer error messages. | |
1268 | ||
1269 | The use of C<:void> with Fatal is discouraged. | |
e92e55da MB |
1270 | |
1271 | =head1 DESCRIPTION | |
1272 | ||
0b09a93a PF |
1273 | C<Fatal> provides a way to conveniently replace |
1274 | functions which normally return a false value when they fail with | |
1275 | equivalents which raise exceptions if they are not successful. This | |
1276 | lets you use these functions without having to test their return | |
1277 | values explicitly on each call. Exceptions can be caught using | |
1278 | C<eval{}>. See L<perlfunc> and L<perlvar> for details. | |
e92e55da MB |
1279 | |
1280 | The do-or-die equivalents are set up simply by calling Fatal's | |
1281 | C<import> routine, passing it the names of the functions to be | |
1282 | replaced. You may wrap both user-defined functions and overridable | |
0b09a93a PF |
1283 | CORE operators (except C<exec>, C<system>, C<print>, or any other |
1284 | built-in that cannot be expressed via prototypes) in this way. | |
e92e55da | 1285 | |
91c7a880 GS |
1286 | If the symbol C<:void> appears in the import list, then functions |
1287 | named later in that import list raise an exception only when | |
1288 | these are called in void context--that is, when their return | |
1289 | values are ignored. For example | |
1290 | ||
0b09a93a | 1291 | use Fatal qw/:void open close/; |
91c7a880 | 1292 | |
0b09a93a | 1293 | # properly checked, so no exception raised on error |
9b657a62 | 1294 | if (not open(my $fh, '<', '/bogotic') { |
0b09a93a PF |
1295 | warn "Can't open /bogotic: $!"; |
1296 | } | |
91c7a880 | 1297 | |
0b09a93a PF |
1298 | # not checked, so error raises an exception |
1299 | close FH; | |
1300 | ||
1301 | The use of C<:void> is discouraged, as it can result in exceptions | |
1302 | not being thrown if you I<accidentally> call a method without | |
1303 | void context. Use L<autodie> instead if you need to be able to | |
1304 | disable autodying/Fatal behaviour for a small block of code. | |
1305 | ||
1306 | =head1 DIAGNOSTICS | |
1307 | ||
1308 | =over 4 | |
1309 | ||
1310 | =item Bad subroutine name for Fatal: %s | |
1311 | ||
1312 | You've called C<Fatal> with an argument that doesn't look like | |
1313 | a subroutine name, nor a switch that this version of Fatal | |
1314 | understands. | |
1315 | ||
1316 | =item %s is not a Perl subroutine | |
1317 | ||
1318 | You've asked C<Fatal> to try and replace a subroutine which does not | |
1319 | exist, or has not yet been defined. | |
1320 | ||
1321 | =item %s is neither a builtin, nor a Perl subroutine | |
1322 | ||
1323 | You've asked C<Fatal> to replace a subroutine, but it's not a Perl | |
1324 | built-in, and C<Fatal> couldn't find it as a regular subroutine. | |
1325 | It either doesn't exist or has not yet been defined. | |
1326 | ||
1327 | =item Cannot make the non-overridable %s fatal | |
1328 | ||
1329 | You've tried to use C<Fatal> on a Perl built-in that can't be | |
1330 | overridden, such as C<print> or C<system>, which means that | |
1331 | C<Fatal> can't help you, although some other modules might. | |
1332 | See the L</"SEE ALSO"> section of this documentation. | |
1333 | ||
1334 | =item Internal error: %s | |
1335 | ||
1336 | You've found a bug in C<Fatal>. Please report it using | |
1337 | the C<perlbug> command. | |
1338 | ||
1339 | =back | |
91c7a880 | 1340 | |
a6fd7f3f RGS |
1341 | =head1 BUGS |
1342 | ||
0b09a93a PF |
1343 | C<Fatal> clobbers the context in which a function is called and always |
1344 | makes it a scalar context, except when the C<:void> tag is used. | |
1345 | This problem does not exist in L<autodie>. | |
a6fd7f3f | 1346 | |
3776a202 PF |
1347 | "Used only once" warnings can be generated when C<autodie> or C<Fatal> |
1348 | is used with package filehandles (eg, C<FILE>). It's strongly recommended | |
1349 | you use scalar filehandles instead. | |
1350 | ||
e92e55da MB |
1351 | =head1 AUTHOR |
1352 | ||
0b09a93a | 1353 | Original module by Lionel Cons (CERN). |
e92e55da | 1354 | |
10af26ed | 1355 | Prototype updates by Ilya Zakharevich <ilya@math.ohio-state.edu>. |
e92e55da | 1356 | |
0b09a93a PF |
1357 | L<autodie> support, bugfixes, extended diagnostics, C<system> |
1358 | support, and major overhauling by Paul Fenwick <pjf@perltraining.com.au> | |
1359 | ||
1360 | =head1 LICENSE | |
1361 | ||
1362 | This module is free software, you may distribute it under the | |
1363 | same terms as Perl itself. | |
1364 | ||
1365 | =head1 SEE ALSO | |
1366 | ||
1367 | L<autodie> for a nicer way to use lexical Fatal. | |
1368 | ||
1369 | L<IPC::System::Simple> for a similar idea for calls to C<system()> | |
1370 | and backticks. | |
1371 | ||
e92e55da | 1372 | =cut |